Preliminary analysis of Beijing MST radar observation results in the mesosphere-lower thermosphere

Beijing MST radar is one of the Chinese Meridian Project constructions of only two domestic MST radars.It was built by Institute of Atmospheric Physics,Chinese Academy of Sciences,located at Xianghe field observatory,Hebei province(39.754°N,116.962°E).System integrated test was finished in May 2011 and completed acceptance in the end of July 2011.After1-month joint tests from 21 September 2011to 20 October 2011,Beijing MST radar operated continuously to observe real-time winds and turbulence in the altitude range of 3.5~10km(low mode),11~25km(middle mode)and 60~90km(even above)(high mode).Beijing MST radar operates at 50 MHz with a peak power of 172 kW and 104 m2 of antenna area.The purpose of thispaper is to investigate the detection capability and data reliability of Beijing MST radar in the mesosphere-lower thermosphere(MLT)region.Two years of data(January 2012 to December 2013)in high mode were used.From the aspect of data acquisition rate,comparison of wind measurements with the nearby Langfang meteor radar and spatial and temporal characteristics of wind,preliminary analyses were made.Analysis results indicate that:(1)Data acquisition rate shows diurnal variation characteristics:during daytime the MST radar can obtain data in 65~100km.High-ratio areas of data acquisition rate were mainly concentrated in the 70~80km with a maximum of up to 80%.At nighttime available data altitude range focused on 80~100km with data acquisition rate at 30% and below.This indicates that the MST radar can detect ionospheric D layer and lower E layer during daytime,at night time D layer disappears,only lower E layer detected.Seasonal variation characteristics of data acquisition rate are that the time and height range of available data were large in summer daytime,followed by spring,and winter was minimum.During summer daytime and until one hour after sunset,the MST radar can detect up to 120 km.(2)Horizontal winds in 80~100km measured by Beijing MST radar and Langfang meteor radar in May 2012 were compared.The results showed good agreement in spatial and temporal distribution,indicating that the data of MST radar observations is reliable.(3)The spatial and temporal distribution of averaged zonal wind and meridional wind of corresponding month in year 2012 and 2013had high consistency,and were also fairly consistent with HWM07 model results.The preliminary analysis results above show that the Beijing MST radar has strong detection ability in the MLT region(60~120km),and the observed data can be furtherly used to reveal the processes and driving factors of the MLT region.